A cryogenic pump comprising a shaft disposed in a bearing. The shaft rotates with respect to the bearing housing, and the shaft includes an end with an angled face. The pump includes a drive at one end of the bearing housing. A tappet passage is formed through the drive housing. A pushrod housing connects to the drive housing. The pump includes a piston and a tappet sliding within the tappet passage. The tappet has a base end disposed within the tappet passage and a rod end extending below the tappet end of the drive housing. A fluid cavity is in the tappet passage between the piston and the tappet. The pump includes a pushrod connected to the tappet. The angled face of the shaft rotates and drives the piston toward the drive housing, pushing fluid within the fluid cavity against the tappet, driving the pushrod away from the drive housing.